How do short sleepers use extra waking hours? A compositional analysis of 24-h time-use patterns among children and adolescents

Adherence to 24-h movement behaviour guidelines in families with multiple children

BACKGROUND

In 2019, the World Health Organization (WHO) launched the first global movement guidelines for children that combined sleep, physical activity and screen time. Our previous research showed that adherence to age-specific guidelines for screen time was challenging for families with children in different age groups. We aimed to determine whether families with children in different age-based movement guideline categories have poorer adherence to the broader 24-h movement guidelines than those with all children in the same age category.

METHODS

Data were from the 1973-1978 cohort of the Australian Longitudinal Study on Women's Health (seventh survey, 2015) and the women's three youngest children (aged ≤12) (Mothers and their Children's Health sub-study, 2016/2017). The sample was 1787 women (families) with 4064 children (mean age 7.2 [SD 2.9]). Whether children in the family were in the same or different age-based category was determined by matching children's ages in a family against age-based guideline categories for the 24-h movement behaviours. The association between children in the family being in the same or different age-based guideline category on adherence to 24-h movement guidelines, both collectively and individually, was analysed by adjusted logistic regression (binary and multinomial).

RESULTS

Families with children in the same age guideline categories had double the odds of having all children meet 24-h movement guidelines (adjusted odds ratio [OR] 1.95 [95% confidence interval, CI: 1.32, 2.86]). Families with children in the same age categories on the screen guideline had higher odds of all children meeting (2.25 [1.73, 2.93]) and lower odds of some meeting/some failing the screen guideline (0.18 [0.14, 0.25]), than families with all children in different age categories. Families with children in the same age categories on the physical activity guideline had lower odds of all children meeting (0.57 [0.43, 0.75]) or some meeting/some failing the physical activity guideline (0.08 [0.06, 0.12]). No associations were found for sleep guidelines.

CONCLUSIONS

Families with multiple children may need practical advice and strategies on how to adhere to guidelines when children span age categories. This could form part of public health strategies that raise awareness of the guidelines and may improve guideline adherence.

Moving beyond moderate-to-vigorous physical activity: the role of light physical activity during adolescence

Regular physical activity is an important component of a healthy lifestyle for young people. However, an estimated 80% of adolescents globally are insufficiently active. Traditionally, health benefits were attributed only to physical activity of at least moderate intensity, and recommendations focused on achieving a threshold of moderate-to-vigorous physical activity, without consideration of other aspects of movement within the 24 h cycle. Recently, the overall daily balance of active and sedentary behaviours has gained recognition as an important determinant of health. However, the relationship between light intensity physical activity and health has not been fully explored. In this perspective paper, we discuss key challenges in defining, measuring and analysing light physical activity which have hindered the advancement of knowledge in this area. Next, we suggest three ways in which light physical activity may enhance adolescent wellbeing: firstly, by replacing sedentary behaviours to increase daily movement; secondly, by supporting the accumulation of higher intensities of physical activity; and thirdly, by providing positive experiences to facilitate lifelong engagement with physical activity. In highlighting the importance of light physical activity during adolescence, we aim to encourage critical reflection and the exploration of new approaches towards physical activity within public health and beyond.

The Goldilocks Day for healthy adiposity measures among children and adolescents

Background

The optimal balance of time spent on daily movement behaviors ("The Goldilocks Day") associated with childhood obesity remains unknown.

Objective

To estimate the optimal durations of sleep, sedentary behavior (SB), light physical activity (LPA), and moderate-to-vigorous physical activity (MPVA) associated with excess adiposity in a paediatric population.

Methods

Accelerometer-measured 24-h movement behaviors were obtained from 659 Czech children and adolescents (8-18-year-olds). Adiposity indicators were body mass index z-score, fat mass percentage, fat-free mass index, and visceral adipose tissue. Excess adiposity was defined as exceeding the 85th percentile for an adiposity indicator. Compositional regression analyses were used investigate the associations between movement behaviors and adiposity indicators and estimating "The Goldilocks Day."

Results

The movement behavior composition was associated with visceral adipose tissue (Fdf1 = 3,df2 = 317 = 3.672, p = 0.013) and fat mass percentage (Fdf1 = 3,df2 = 289 = 2.733, p = 0.044) among children and adolescents. The Goldilocks Day consisted of 8.5 h of sleep, 10.8 h of SB, 3.9 h of LPA, and 0.8 h of MVPA among children and 7.5 h of sleep, 12.4 h of SB, 3.6 h of LPA, and 0.5 h of MVPA among adolescents.

Conclusion

Optimizing the time spent sleeping, and in sedentary and physical activities appears to be important in the prevention of excess adiposity.

Paths towards a healthier BMI among short and adequate sleepers: A pathway network analysis considering movement behaviors in low-income preschoolers

INTRODUCTION

Short sleep duration has been seen as a predictor of higher body mass index (BMI) in youth. Sleep duration varies substantially along early childhood, and the paths towards a healthier BMI, considering the other movement behaviors (physical activity-PA and screen time) are unexplored in preschoolers.

AIM

To construct a sleep-BMI model to capture the direct and indirect paths to intervening towards a healthier BMI, according to low-income preschoolers' compliance with the other movement behaviors.

METHODS

Two hundred and seventy two preschoolers (4.5 ± 0.0; 138 boys) participated in the study. Sleep and screen time (ST) were assessed in a face-to-face interview with primary caregivers. PA was assessed using accelerometer (wGT3X-BT). Preschoolers were categorized as compliant or not with sleep, screen time, total and moderate to vigorous PA recommendations. BMIz-score was calculated according to preschoolers' sex and age. All the assessed variables, besides sex and age were included in a Network Pathway Analysis (NPA) according to age as nodes.

RESULTS

At 3 years old, a direct and negative path between sleep-BMIz score was observed. At four and 5 years old, this relationship became positive. Further, girls were more compliant with sleep, ST and total PA recommendations. Total PA (TPA) showed the highest expected influence value in the general, 3 and 4 years old NPA.

CONCLUSION

The NPA analysis showed different directions for the relationship between sleep and BMIz score, according to age. Intervention strategies to a healthier BMI among preschoolers compliant or not with sleep recommendations should focus in increasing TPA.

A 24-h activity profile and adiposity among children and adolescents: Does the difference between school and weekend days matter?

BACKGROUND

Twenty-four-hour movement behaviours are gaining attention in the research community. However, no study has addressed how 24-h activity profiles vary between structured and less structured days and whether an unfavourable activity profile is associated with childhood obesity. We aimed to analyse differences between school day and weekend day 24-h activity profiles and their associations with adiposity indicators among children and adolescents.

METHODS

Participants were 382 children and 338 adolescents who wore wrist accelerometers for 24 hours a day for seven consecutive days. The 24-h activity profile expressed by the average acceleration (AvAcc) and intensity gradient (IG) were estimated from multi-day raw accelerometer data. Adiposity indicators included body mass index (BMI) z-score, fat mass percentage (FM%), fat mass index (FMI), and visceral adipose tissue (VAT). Multiple linear regression of activity profile metrics and adiposity indicators was performed separately for school and weekend days.

RESULTS

Weekend days AvAcc and IG were lower compared to school days in both age groups (p <0.001 for all). Specifically, AvAcc was lower by 9.4% and 11.3% in children and adolescents, respectively. IG on weekend days was lower (more negative) by 3.4% in children and 3.1% in adolescents. Among children, on school days AvAcc and IG were negatively associated with FM%, FMI, and VAT, whilst on weekend days AvAcc was positively associated with BMI z-score, FMI, and VAT (p < 0.05 for all). Among adolescents, negative associations were found between weekend day AvAcc and IG and FM% and FMI (p < 0.05 for all), respectively.

CONCLUSIONS

This study confirms the importance of 24-h activity profile as a potentially protective factor against excess adiposity. The variability of movement behaviours during structured and less structured days should be considered when optimizing the 24-h movement behaviours to prevent childhood obesity.

Changes in physical activity patterns of students from primary to secondary school: a 5-year longitudinal study

This study aimed to annually examine anthropometric characteristics and physical activity (PA) among children transitioning from fourth grade (9–10 years of age) to eighth grade (13–14 years of age) in Japan. The participants’ (n = 63) age, grade, sex, weight, height, and weight status were recorded at baseline. Accelerometry assessments were performed annually following established protocols. Time spent on activities requiring ≥ 3 metabolic equivalents (METs), 1.6–2.9 METs, and ≤ 1.5 METs were defined as moderate-to-vigorous intensity PA (MVPA), light PA (LPA), and sedentary behavior (SB), respectively. Two linear mixed models were used to examine whether MVPA, LPA, and SB min/day changed over time. Fifty-five participants provided complete data. A significant, nonlinear, longitudinal decline in MVPA, an increase in SB, and a linear decline in LPA were observed. Changes in MVPA and SB were accelerated in seventh grade (12–13 years of age). Male sex and maintenance of normal weight status were associated with higher MVPA levels. Changes in LPA and SB were not associated with sex or weight status. During the transition period from primary to secondary school, MVPA and SB showed nonlinear accelerations. Sex and normal weight were associated with more time spent performing MVPA.

Childhood obesity prevention: what can be achieved?

PURPOSE OF REVIEW

Childhood obesity is a pandemic generating an enormous individual and socioeconomic burden worldwide. This narrative review summarizes recent evidence on successful and recommended prevention strategies according to age groups and different levels of interventions.

RECENT FINDINGS

Effective prevention of childhood obesity is feasible and most successful early in life up to preschool age, and it should include a multicomponent approach, integrating individuals, family and society. Trials that improve nutrition and/or enhance physical activity are the cornerstones of childhood obesity prevention on an individual level. However, their efficacy is determined by the combination of interventions for the target age group. Further, improving family support and sleep, as well as reducing screen time, lead to favourable results. Many research gaps remain, including a lack of effective interventions for high-risk groups.

SUMMARY

As a multifactorial condition, childhood obesity requires a multicomponent approach. Interventions should be developmental stage-specific and adjusted to the setting. Current research gaps need to be targeted by future trials, with a special focus on the benefit of the most vulnerable groups. From a systems response perspective, a paradigm shift from interventions focusing on the individual to approaches that target society as a whole is warranted.

Sleep, sedentary behavior, and physical activity in Brazilian adolescents: Achievement recommendations and BMI associations through compositional data analysis

Physical activity, sedentary behavior (SB), and sleep are habitual human behaviors (HHB) which are modifiable throughout the different life phases. Therefore, it is necessary to analyze how the time distribution throughout the day among HHB may be associated with body mass index (BMI). These results could provide inferences which can guide interventions that trigger changes in adolescent behaviors in favor of their health. The objective of this study was to verify the proportion of adolescents who meet the recommendation of sleep, moderate to vigorous physical activity (MVPA), and screen time (ST); to analyze the associations between HHB and BMI, and to determine possible changes in BMI associated with time reallocation between different HHB. Daily HHB recommendations (yes/no) were analyzed by frequency distribution. Compositional data analyses were used to examine the association between HHB and the BMI z-score (zBMI) with covariates (sex, age, and socioeconomic status). Compositional isotemporal substitution models estimated the change in zBMI associated with HHB reallocations from 15 to 120 minutes. A total of 185 adolescents were included (15 to 18 years, 50.8% boys). Thus, total sleep time, SB, light physical activity (LPA) and MVPA were measured by 24-hour accelerometry for seven consecutive days. ST, demographic characteristics, and socioeconomic status were assessed using a questionnaire. Sleep, MVPA, and ST recommendations were achieved by 32.97%, 8.10%, and 1.08% of the sample, respectively. No adolescent was able to achieve all of the daily recommendations. Age was significantly and positively associated with zBMI (p<0.001). Simply replacing 75, 90, and 120 minutes of MVPA by LPA led to an estimated significant increase in zBMI (95CI% z-value, 0.01 to 1.49). The HHB relocation estimates in 24h did not show positive effects on zBMI, nor did it increase the time engaged in MVPA, which may raise the hypothesis that other parameters related to obesity and their related interactions need to be better understood.

Effects of Movement Behaviors on Overall Health and Appetite Control: Current Evidence and Perspectives in Children and Adolescents

PURPOSE OF REVIEW

To present the definitions and recommendations for movement behaviors in children and adolescents, including physical activity (PA), sedentary behaviors (SB), and sleep, and to provide an overview regarding their impact on health and obesity outcomes from childhood to adulthood, as well as interactions with appetite control.

RECENT FINDINGS

PA represents a variable proportion of daily energy expenditure and one can be active with high SB or vice versa. Studies have described movements across the whole day on a continuum from sleep to SB to varying intensities of PA. More PA, less SB (e.g., less screen time) and longer sleep are positively associated with indicators of physical health (e.g., lower BMI, adiposity, cardiometabolic risk) and cognitive development (e.g., motor skills, academic achievement). However, less than 10% of children currently meet recommendations for all three movement behaviors. Movement behaviors, adiposity, and related cardiometabolic diseases in childhood track into adolescence and adulthood. Furthermore, low PA/high SB profiles are associated with increased energy intake. Recent studies investigating energy balance regulation showed that desirable movement behavior profiles are associated with better appetite control and improved eating habits. Early identification of behavioral phenotypes and a comprehensive approach addressing all key behaviors that directly affect energy balance will allow for individual strategies to prevent or treat obesity and its comorbidities. Investigating exercise as a potential "corrector" of impaired appetite control offers a promising weight management approach.

Surveillance of physical activity and sedentary behaviour in czech children and adolescents: a scoping review of the literature from the past two decades

BACKGROUND

This study aimed to map the available evidence related to physical activity (PA) and sedentary behaviour (SB) in Czech children and adolescents and suggest future directions and improvements to strengthen the surveillance of PA and SB in the Czech Republic.

METHODS

The search of articles published between January 2000 and December 2020 included the Medline and Medvik databases and a manual search in eight Czech journals related to the topic. This review followed the "Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews".

RESULTS

Out of 350 identified articles, 79 articles met the criteria for selection and referred to 27 studies. The majority of the articles were cross-sectional (89%), approximately two-thirds of the articles (61%) examined only PA, and half of the articles (51%) employed device-based assessments. Approximately 47% of the articles reported the prevalence of physical inactivity on the basis of inconsistently defined recommendations. Approximately 14%, 23%, and 10% of the articles focused on active transportation, organized PA (including physical education or leisure-time PA), and parent-child PA, respectively.

CONCLUSIONS

Future studies need to focus on longitudinal design and interventions, randomly selected samples, a mix of device-based and self-reported methods, and the recognition of health-related 24-hour time use patterns. This review advocates the government-supported development of a national surveillance system that will help to reduce insufficient PA and excessive SB.

Changes in sedentary behavior patterns during the transition from childhood to adolescence and their association with adiposity: a prospective study based on compositional data analysis

Background

To date, no longitudinal study using a compositional approach has examined sedentary behavior (SB) patterns in relation to adiposity in the pediatric population. Therefore, our aims were to (1) investigate the changes in SB patterns and adiposity from childhood to adolescence, (2) analyze the prospective compositional associations between changes in SB patterns and adiposity, and (3) estimate the changes in adiposity associated with substituting SB with physical activity (PA) of different intensities.

Methods

The study presents a longitudinal design with a 5-year follow-up. A total of 88 participants (61% girls) were included in the analysis. PA and SB were monitored for seven consecutive days using a hip-worn accelerometer. Adiposity markers (fat mass percentage [FM%], fat mass index [FMI], and visceral adiposity tissue [VAT]) were assessed using the multi-frequency bioimpedance analysis. The prospective associations were examined using compositional data analysis.

Results

Over the follow-up period, the proportion of time spent in total SB increased by 154.8 min/day (p < 0.001). The increase in total SB was caused mainly by an increase in middle and long sedentary bouts, as these SB periods increased by 79.8 min/day and 62.0 min/day (p < 0.001 for both), respectively. FM%, FMI, and VAT increased by 2.4% points, 1.0 kg/m², and 31.5 cm² (p < 0.001 for all), respectively. Relative to the remaining movement behaviors, the increase in time spent in middle sedentary bouts was significantly associated with higher FM% (β_ilr1 = 0.27, 95% confidence interval [CI]: 0.02 to 0.53) at follow-up. Lower VAT by 3.3% (95% CI: 0.8 to 5.7), 3.8% (95% CI: 0.03 to 7.4), 3.9% (95% CI: 0.8 to 6.9), and 3.8% (95% CI: 0.7 to 6.9) was associated with substituting 15 min/week spent in total SB and in short, middle, and long sedentary bouts, respectively, with an equivalent amount of time spent in vigorous PA.

Conclusions

This study showed unfavorable changes in SB patterns and adiposity status in the transition from childhood to adolescence. Incorporating high-intensity PA at the expense of SB appears to be an appropriate approach to reduce the risk of excess adiposity in the pediatric population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13690-021-00755-5.

Movement behaviors in short versus adequate nocturnal sleepers: A compositional analysis of preschoolers

BACKGROUND

Accruing adequate daily amounts of time spent on movement behaviors (physical activity (PA), sedentary behavior (SB), and sleep) in childhood has been associated with positive short and long-term health outcomes. Nonetheless, how waking time is distributed across PA and SB among preschoolers who are short and adequate sleepers at night is unknown.

AIM

This study investigated: (1) if there are differences in a movement behaviors composition among adequate and short nocturnal sleepers; and (2) the association between preschoolers' time spent in PA, SB, and sleep among adequate and short nocturnal sleepers.

METHODS

A total of 270 preschoolers (132 boys; 3.97 ± 0.81 years old; 15.48 ± 1.62 kg/m² ) participated in this study. PA and SB were assessed using accelerometry (model wGT3X). Sleep duration was assessed through a parental-proxy interview, and preschoolers were stratified as short and adequate sleepers, according to attendance to international sleep duration guidelines. Compositional data analysis was used to explore the time-use patterns of behaviors among adequate and short sleepers.

RESULTS

Short sleepers spent 64 min less time asleep, accumulated 32 min in more sedentary time (p = .005, Cohen's d = 0.36, Bayes Factor: 6.17), and 24 min more in light PA (p = .0005, Cohen's d = 0.44, Bayes Factor: 46.37) compared to adequate sleepers.

CONCLUSIONS

Being a short sleeper was associated with greater time spent in SB and light PA during their waking hours. The health implications of movement behaviors composition among short sleep preschoolers should be further investigated.

Associations of novel 24-h accelerometer-derived metrics with adiposity in children and adolescents

Background

Further research is required to explore the associations between 24-h movement behaviours and health outcomes in the paediatric population. Therefore, this study aimed to examine the associations between novel data-driven 24-h activity metrics and adiposity among children and adolescents.

Methods

The sample included 382 children (8–13 years) and 338 adolescents (14–18 years). The average acceleration (AvAcc) of activity, intensity gradient (IG), and metrics representing the initial acceleration for the most active time periods of the 24-h cycle were calculated from raw acceleration data. Adiposity measures included body mass index z-score, fat mass percentage (FM%), and visceral adipose tissue (VAT). Data analysis was performed using multiple linear regression adjusted for wear time, sex, maternal education level, and maternal overweight and obesity.

Results

Children demonstrated higher values in all 24-h activity metrics than did adolescents (p < 0.001 for all). For children, the initial acceleration for the most active 2, 5, 15, and 30 min of the 24-h cycle were negatively associated with FM% (p ≤ 0.043 for all) and VAT (p <0.001 for all), respectively. For adolescents, the IG was negatively associated with FM% (p = 0.002) and VAT (p = 0.007). Moreover, initial acceleration for the most active 2, 5, 15, 30, 60, and 120 min were associated with FM% (p ≤ 0.007 for all) and with VAT (p ≤ 0.023 for all).

Conclusions

The intensity distribution of activity and initial acceleration for the most active 2, 5, 15, 30, 60, and 120 min within the 24-h cycle are beneficial for the prevention of excess adiposity in the paediatric population.

Czech adolescents' remote school and health experiences during the spring 2020 COVID-19 lockdown

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One in five adolescents reported economic disruptions during spring 2020 lockdown.

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Girls and older adolescents reported the worst social and mental well-being.

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Perceived change in sleep and physical activity varied by gender and behavior.

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Adolescents reported consuming more fruits and vegetables and less energy drinks.

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Findings can be used for time trends that include the lockdown period.

Schools around the world were closed during the spring 2020 lockdown to reduce the spread of COVID-19. As such, these rapid changes to adolescent daily routines may have had immediate as well as long-term effects on their physical, social, and mental health. Therefore, the aim of this study was to examine the experiences, health behaviors and perceived change in health behaviors among adolescents in Czechia during the spring 2020 lockdown. Adolescents (n = 3,440, 54% girls; M_age = 13.5 years, SD = 1.6) from all regions of Czechia were recruited to complete a self-report survey based on the Health Behaviour in School-aged Children study, with additional items on household disruptions and socialization during lockdown, as well as items on perceived changes in health behaviors during lockdown. First, we described the self-reported impacts of the spring lockdown by gender and grade. Second, log-linear analyses were used to examine the perceived behavioral changes based on standardized cut-off values reporting for health behaviors and gender. Less than a third, 19% and 32% of the respondents reported economic and psychosocial disruptions to their family life, 79% indicated they had positive opportunities for family interactions or learning new things. Girls and older adolescents reported the worst levels of social and mental well-being. Changes in respondents’ perceived health behaviors varied by reported behavior frequencies and gender. These results may be useful to compare with future secular trends, and may serve as input in developing strategies to counter the impact of the spring 2020 or future similar lockdowns on the adolescents' well-being..

How do adolescents with short sleep duration spend their extra waking hours? A device-based analysis of physical activity and sedentary behaviour in a Brazilian sample

Objectives

To compare sedentary behaviour and physical activity between short sleepers and adequate sleepers in a sample of Brazilian adolescents.

Material and Methods

688 adolescents wore accelerometers on the non-dominant wrist for seven days. Sleep duration, sedentary behaviour, light (LPA), moderate (MPA), and vigorous physical activity (VPA) were estimated. Participants were classified as short (<8h/night) or adequate sleepers (≥8h/night). The minutes and the percentage of time spent in each waking behaviour was compared between short and adequate sleepers.

Results

Participants were 16.3 years old, 50.4% were female, and 67.7% were short sleepers. Adequate sleepers engaged in less (min/day) sedentary behaviour (-53.46), LPA (-25.44), MPA (-4.27), and VPA (-0.63) compared to short sleepers. However, no differences were observed for the proportion of time (68% in sedentary behaviour, 28% in LPA, 3% in MPA, and <0.4% in VPA).

Conclusion

Patterns of waking behaviours are similar between short and adequate sleepers.

Replacing school and out-of-school sedentary behaviors with physical activity and its associations with adiposity in children and adolescents: a compositional isotemporal substitution analysis

BACKGROUND

Little is known on how context-specific sedentary behaviors (SB) affect adiposity. This study aimed to investigate compositional associations between context-specific SB and adiposity and estimate the differences in adiposity associated with replacing school and out-of-school SB with physical activity (PA).

METHODS

This study included 336 children and adolescents. Time spent in SB and PA was estimated using multi-day 24-hour raw accelerometer data. SB and PA were specified for school and out-of-school times. Fat mass percentage (FM%) and fat mass index (FMI) were used as adiposity indicators. A compositional isotemporal substitution model was used to estimate differences in adiposity associated with one-to-one reallocations of time from context-specific SB to PA.

RESULTS

Participants spent approximately two thirds of their school and out-of-school time being sedentary. Relative to the remaining 24-h movement behaviors, significant associations between out-of-school SB and adiposity were found in both boys (β_ilr1 = 0.63, 95% confidence interval [CI] = 0.03-1.22 for FM%; β_ilr1 = 0.76, 95% CI = 0.03-1.49 for FMI) and girls (β_ilr1 = 0.62, 95% CI = 0.25-0.98 for FM%; β_ilr1 = 0.80, 95% CI = 0.28-1.32 for FMI). Replacing 30 min/day of out-of-school SB with out-of-school light PA decreased FM% by 10.1% (95% CI = 3.3-17.9) and FMI by 14% (95% CI = 2.7-24) in girls. No significant associations were found for school SB.

CONCLUSIONS

A reduction of out-of-school SB in favor of light PA should be advocated as an appropriate target for interventions and strategies to prevent childhood obesity.

A Model of Adolescent Sleep Health and Risk for Type 2 Diabetes

PURPOSE OF REVIEW

This paper presents a review of the current literature in support of a model explaining the relationships between sleep health and risk for type 2 diabetes in adolescents.

RECENT FINDINGS

Short sleep duration is associated with risk of developing obesity in youth. Sleep restriction increases energy expenditure, but also increases hunger, appetite, and food intake, causing positive energy balance, impacting appetite-regulating hormones, and leading to increased eating late at night. Insufficient sleep may lead to reduced physical activity and greater sedentary behaviors. In addition, short sleep duration is associated with reduced insulin sensitivity. The cumulative negative consequences of insufficient sleep increase risk for type 2 diabetes. Applications to clinical care, public policy, and future research are discussed. Insufficient sleep in adolescence increases risk for type 2 diabetes directly through impact on insulin sensitivity and indirectly through increased dietary intake, sedentary activity, and weight gain.

The Prevalence of Insufficient Sleep and Bedtime Delay Among Kindergarten Children Aged 3 to 6 Years in a Rural Area of Shanghai: A Cross-Sectional Study

Introduction: Sleep deprivation in children is a global public health problem that affects the physical and mental development of children. Bedtime delay induced by longer screen time and heavy study load is a common cause of sleep deprivation in children. However, the prevalence of insufficient sleep and bedtime delay and related influencing factors among kindergarten children is limited in Shanghai, China. Methods: In 2018, we selected 8,586 children aged 3 to 6 years and their parents in Songjiang District, Shanghai. Data was collected among parents by face-to-face questionnaire interview with signed informed consent. We defined insufficient sleep as those who slept for < 10 h in children aged 3-5 years or 9 h in children aged 6 years within 24 h, and we define bedtime delay as children with bedtime after 21:00. SAS 9.1.3 software was used to calculate the prevalence of bedtime delay and insufficient sleep, and logistic regression was used to explore potential influencing factors. Results: The prevalence of insufficient sleep and bedtime delay among children aged 3 to 6 years was 11.67 and 56.85%, respectively. The prevalence of insufficient sleep among boys was slightly higher than among girls [odds ratio (OR) = 1.18, 95% confidence interval (CI): 1.04-1.35]. With the increase of the age of children, the prevalence of insufficient sleep increased gradually (P < 0.05). The prevalence of insufficient sleep was higher among the only child in the family (OR = 1.18, 95% CI: 1.02-1.36) and those with longer hours of TV watching (OR = 109, 95% CI: 1.02-1.16). Meanwhile, the prevalence of bedtime delay was also higher among the only child in the family (OR = 1.17, 95% CI: 1.06-1.79), among those with parents accompanying for sleep (OR = 1.21, 95% CI: 1.10-1.34), and those with longer TV watching time (OR = 1.13, 95% CI: 1.07-1.18). Conclusions: Insufficient sleep and bedtime delay were prevalent in Chinese children aged 3 to 6 years, especially in boys and older children. TV watching as well as parents accompanying for sleep were associated with insufficient sleep and bedtime delay. We recommend that parents should limit the screen time of children, advocate earlier bedtime and later morning wake-up among children, as well as make their children sleep in separate beds or rooms in younger age.

Prevalence and correlates of adherence to the combined movement guidelines among Czech children and adolescents

Background

There are limited studies on the prevalence of adherence to the combined guidelines for physical activity (PA), sedentary behavior, and sleep in children and adolescents. Moreover, little is known about correlates of adherence to the guidelines. Therefore, the main aim of this study is to examine the prevalence and identify the correlates of adherence to the combined movement guidelines among children and adolescents.

Methods

A total of 355 children aged 8–13 years (44% boys) and 324 adolescents aged 14–18 years (43% boys) from the Czech Republic participated in this study. PA and sleep duration were estimated using multi-day 24-h raw data from wrist-worn accelerometers. Recreational screen time was parent proxy-reported in children and self-reported in adolescents. Seventeen potential correlates were grouped into three homogenous categories for biological and cognitive, behavioral, and family correlates. The multi-level multivariable logistic regression was applied to identify correlates of adherence to combined movement guidelines and to specific combinations of any of two recommendations.

Results

Approximately 6.5% of children and 2.2% of adolescents met all recommendations of the combined movement guidelines. In children, girls (OR = 0.4; 95% CI = 0.1–0.9) and participants with overweight or obese fathers (OR = 0.3; 95% CI = 0.1–0.7) had significantly lower odds of adherence to the combined movement guidelines. Additionally, children had higher odds of meeting specific combinations of two recommendations if they reported regular fruit and vegetable intake, participated in organized PA, or if their fathers had a university degree. Meanwhile, paternal overweight and obesity, and high sleep efficiency were associated with lower odds of meeting specific combinations of recommendations. In adolescents, sex, fruit and vegetable intake, organized PA, and active play were correlates of meeting specific combinations of any two recommendations.

Conclusions

A low proportion of children and adolescents met the combined movement guidelines and several correlates related to family were identified. Family is a key source of influence for healthy movement behaviors during childhood and adolescence.